fix(rcar3-drivers): check "rcar_image_number" variable before use

Validate the content of rcar_image_number variable before use.

Reviewed-by: Tomer Fichman <Tomer.Fichman@cymotive.com>
Signed-off-by: Yoshifumi Hosoya <yoshifumi.hosoya.wj@renesas.com>
Change-Id: Ieeabafa8f709d25eebc4a8e490bf623ef32ccf9f
1 file changed